1. Field of the Invention
The present invention relates to a structure of an electrode compartment in a filter press type electrolytic cell for electrolyzing an alkali metal chloride.
2. Description of the Prior Arts
An electrode compartment comprises a frame having means for feeding an electrolyte, a frame for discharging an electrolyzed product and electrode assembly of an electrode and current lead bars for electrically connecting the electrode to a power source (hereinafter referring to as lead bars). The ends of the lead bars should be projected through the frame to electrically connect to the power source.
On the other hand, it is preferable to reduce the width of the frames for forming the electrode compartment in view of reducing a space for setting the apparatus; reducing a weight of the electrolytic cell; reducing cost for the apparatus; and increasing efficiency in the same size of the electrolytic cell.
In the electrode compartment holding the above-mentioned electrode assembly in the frames, it is necessary to have the structure for removing, speedily, the gas generated by the electrolysis, out of the electrode compartment so that the increase of the electrolytic voltage caused by the gas is prevented.
Various arrangements of the lead bars and the flow of the electrolyte can be considered to attain said purpose. It is considered to arrange the lead bars to be substantially perpendicular to the lifting flow of the electrolyte in the electrode compartment for feeding the electrolyte through the lower frame and discharging the electrolyzed product through the upper frame.
However, it is usual that the frames have a structure having longer horizontal length for said electrode compartment. When the lead bars are formed to be economical (the material for the lead bars is expensive), the sectional area of the lead bar for passing the current is small. The length of the lead bars for passing the current is long when the lead bars are set in horizontal direction (structure of frames having longer horizontal length). Accordingly, a voltage drop in the lead bars is large and the efficiency of the electrolytic cell is lowered, disadvantageously.
The inventors have studied to obtain a structure of an electrode compartment from which the gas generated can be removed speedily, without increasing a width of the frames, in view of arrangements of the lead bars, shapes of the lead bar and assembling of the lead bars.